Confidence intervals, charted

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.27.0/lattice-grid.min.css">

<div id="app"></div>

<script type="module">
  import React from 'https://esm.sh/react@18';
  import { createRoot } from 'https://esm.sh/react-dom@18/client';
  import { createGrid, createStat } from 'https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.27.0/lattice-grid.esm.min.js';
  import createLatticeGrid from 'https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.27.0/modules/react.esm.min.js';
  import { createChart } from 'https://cdn.jsdelivr.net/npm/@toclocoinc/lattice-grid@1.27.0/modules/charts.esm.min.js';

  const LatticeGrid = createLatticeGrid({ React, createGrid });

  const columns = [
    { field: 'supplier', title: 'Supplier', filter: { type: 'set' } },
    { field: 'days', title: 'Lead time', type: 'number', format: { suffix: ' d', maximumFractionDigits: 1 }, total: 'avg' },
  ];

  const rows = [/* e.g. [{ id: 'O0', supplier: 'Kestrel', days: 3.1 }, ...] */];

  function App() {
    const gridRef = React.useRef(null);

    React.useEffect(() => {
      const grid = gridRef.current.grid;
      const tile = document.getElementById('tiles').appendChild(document.createElement('div'));

      // interval() is the range the mean is pinned to, computed over the filtered
      // rows. The tile shows it under the value; ask for a proportion with
      // { kind: 'proportion' } and a rule for what counts as a success.
      createStat({ grid, container: tile, title: 'Mean lead time', of: 'days', fn: 'avg',
        interval: (value, grid) => grid.statistics.interval('days'), footer: '95% confidence interval' });

      // error: true draws each mean's interval as a whisker, computed from the
      // readings behind the bar. The chart reads the same grid as the tile, so
      // the bars and the whiskers follow the filters.
      createChart({ grid, container: '#chart', type: 'bar', x: 'supplier', y: { col: 'days', fn: 'avg' },
        error: true, title: 'Mean lead time by supplier, with confidence interval' });
    }, []);

    return (
      <>
        <div id="chart" style={{ height: '250px' }} />
        <div id="tiles" style={{ display: 'grid', gridTemplateColumns: 'repeat(3, 1fr)', gap: '12px', margin: '14px 0' }} />
        <LatticeGrid
          ref={gridRef}
          rowKey="id"
          toolPanel={{ side: 'left', panels: ['filters', 'columns', 'statistics'] }}
          columns={columns}
          rows={rows}
          style={{ height: '340px' }}
        />
      </>
    );
  }

  createRoot(document.getElementById('app')).render(<App />);
</script>